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published_or_final_version / Community Medicine / Master / Master of Public Health

Thesis (M.A.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (February 5, 2007) Includes bibliographical references.

Submitted by Alexandre Sousa (alexandre.sousa@incqs.fiocruz.br) on 2014-08-01T14:25:54Z No. of bitstreams: 1 Tese Waldyr.pdf: 1037034 bytes, checksum: 0951d0a31dbee3d54d18141b2e411b8d (MD5) / Made available in DSpace on 2014-08-01T14:25:54Z (GMT). No. of bitstreams: 1 Tese Waldyr.pdf: 1037034 bytes, checksum: 0951d0a31dbee3d54d18141b2e411b8d (MD5) Previous issue date: 2014 / Rio de Janeiro. Secretaria de Estado de Desenvolvimento Regional, Abastecimento e Pesca / No presente trabalho, foi realizada uma revisão bibliográfica sobre o vírus influenza, enfatizando sua ação e correlacionando-o com as espécies aviárias, com enfoque diferenciado para os pombos domésticos (Columba livia domestica). Alguns aspectos tais como as condições ambientais, o estreito contato com o homem e a disseminação destas aves nos centros urbanos e em diferentes pontos do mundo, foram considerados. Durante o estudo da interação entre homens e pombos, outro agente patogênico mereceu atenção, por ocasião da revisão bibliográfica e por ser considerado o impacto financeiro causado na avicultura, o vírus da doença de Newcastle. Concomitante à revisão, foram analisadas 322 amostras de fezes de pombos, coletadas em praças públicas em várias áreas do município do Rio de Janeiro. Para tal análise foram utilizadas diferentes técnicas, tais como: inoculação em ovos embrionados, hemaglutinação, inibição da hemaglutinação e reação da polimerase em cadeia. As amostras testadas não apresentaram atividade hemaglutinante, bem como, não apresentaram positividade para a presença do vírus influenza e nem para o vírus da Doença de Newcastle, quando submetidas à prova de PCR. Com isto, pôde-se verificar a inexistência dos vírus na população de aves estudada, o que demonstrou não oferecer risco potencial para transmissão destas patologias, no presente momento. / In the present work, influenza was carried through a bibliographical revision on the virus, emphasizing its action and correlating it with the avian species, with approach differentiated for the domestic pigeons (Columba livia domestica). Some aspects such as the ambient conditions, the narrow contact with the man and the dissemination of these birds in the urban centers at different points of the world had been considered. During the study of the interaction between men and pigeons, another pathogenic agent had deserved attention, for occasion of the bibliographical revision, to caused financial impact in the poultry keeping, the virus of Newcastle disease. Concomitant to the bibliographical revision, 322 excrement samples had been analyzed of pigeons, collected in public squares in some areas of the city of Rio de Janeiro. For such analysis, different techniques had been used, such as: inoculation in embrionatted eggs, hemaglutination, inhibition of the hemaglutination and polymerase chain reaction. The tested samples had not presented hemaglutination activity, as well as, had not presented positivism for the presence of the virus influenza and nor for the Newcastle virus when submitted to the test of PCR. With this, the inexistence of the viruses in the studied population of birds could not be verified, what it demonstrated not to offer potential risk for transmission of these pathologies, in the present moment.

Objetivos. Determinar las características clínicas y demográficas de la neumonía por el virus de influenza AH1N1/2009 pandémico en un hospital de referencia de Perú. Materiales y métodos. Se realizó un estudio serie de casos en niños hospitalizados por neumonía por influenza AH1N1/2009 pandémico en un hospital de referencia. Revisamos las historias clínicas entre los meses de junio a septiembre 2009. Todos los casos tuvieron confirmación virológica. Resultados. Se encontró 74 casos de neumonía por el virus de Influenza AH1N1/2009 pandémico (NVIp), de los cuales 50 tuvieron el diagnóstico de neumonía adquirida en la comunidad viral (NACv) y 24 con neumonía nosocomial viral (NNv) de los cuales 16 requirieron ventilación mecánica. Fallecieron 12, todos ellos con antecedentes de comorbilidad. Los casos NNv presentaron asociación estadística con mortalidad. En los casos NACv, los menores de 6 años representaron 72 % (36/50). La mediana de tiempo de enfermedad fue de 5 días. Los síntomas más frecuentes fueron fiebre, tos, rinorrea. Recibieron oseltamivir el 82 %. En la radiografía de tórax el 48 % de los casos presentó infiltrado en parches y el 44 % infiltrado intersticial en la radiografía de tórax. La proteína C reactiva (PCR) mayor a 10mg/L tuvo una asociación significativa con insuficiencia respiratoria (p <0,05). Conclusiones. Encontramos casos NNv quienes tuvieron mayor mortalidad, también los que presentaron el PCR elevado y los que presentaron condición preexistente. / ObjectiveTo determine the clinical and demographic characteristics of pneumonia with influenza virus AH1N1/2009 pandemic at the National Institute of Child. Methods. Retrospective case series in children hospitalized for influenza pneumonia pandemic AH1N1/2009 in a pediatric hospital. Reviewed the medical records between the months of June to September 2009. All cases had virological confirmation, we describe the clinical characteristics and conditions of severity. Results. A total of 74 children of pneumonia with influenza virus AH1N1/2009 pandemic (NVIp), of those 50 were community acquire pneumonia viral (NACv) and 24 pneumonia nosocomial viral (NNv), 16 required mechanical ventilation. 12 died, all had preexisting factors. NN cases showed statistical association with mortality. The most frequent factors were malnutrition, respiratory infections, congenital heart disease and neurological deficits In NACv cases the children under 6 years accounted for 72% (36/50). The median disease duration was 5 days. The most frequent symptoms were fever, cough, runny nose. Received oseltamivir 82%. The chest radiograph 48% of cases showed patchy infiltrates and 44% interstitial infiltrate on chest radiograph. Protein c reactive (CRP) more than 10mg / L was significantly associated with respiratory failure (p <0.05). Conclusions. Cases of NN found who had more mortality, even those who had the highest PCR and those with preexisting condition.

An important characteristic of influenza A is its ability to escape host immunity through antigenic drift. A novel influenza A strain that causes a pandemic confers full immunity to infected individuals, yet because of antigenic drift, these individuals have decreased immunity to drifted strains. We compute the required decrease in immunity so that a recurrence is possible. Models for influenza A must make assumptions on the host contact structure on which the disease spreads. By computing the reproduction number, we show that the classical random mixing assumption predicts an unrealistically large decrease of immunity before a recurrence is possible. We improve over the classical random mixing assumption by incorporating a contact network structure. A complication of contact networks is correlations induced by the initial pandemic. Thus, we provide a novel analytic derivation of such correlations and show that contact networks may require a dramatically smaller drop in immunity before recurrence. Hence, the key new insight is that on contact networks the establishment of a new strain is possible for much higher immunity levels of previously infected individuals than predicted by the commonly used random mixing assumption. This suggests that stable contacts like classmates, coworkers and family members are a crucial path for the spread of influenza in human population. / Graduate

Memoria para optar al Título Profesional de Médico Veterinario / El virus de la influenza porcina o SIV (Swine Influenza Virus), es un patógeno que afecta el sistema respiratorio y produce una de las enfermedades más prevalentes a nivel de industria porcina. Está distribuido en todo el mundo y genera importantes pérdidas económicas. Además, SIV se considera un patógeno zoonótico con potencial pandémico. A partir del brote de influenza humana A H1N1 ocurrida el año 2009, ha surgido la necesidad de conocer y entender las dinámicas de evolución y transmisión de este virus, para beneficio de la salud humana y animal. Realizar un estudio en Chile adquiere especial relevancia, ya que se necesita conocer la realidad actual de SIV en los planteles de producción intensiva de cerdos. El presente estudio tiene como objetivo detectar y aislar virus de Influenza A en la población de cerdos de la zona central de Chile, territorio en donde se concentra la gran mayoría de los planteles de producción intensiva. Para esto se obtuvieron muestras de hisopos nasales y fluidos orales desde 6 granjas ubicadas en esta zona (regiones V, RM, VI y VII) entre el año 2014-2015 en distintas épocas del año. Se utilizó RT-PCR en tiempo real para detectar el virus y se aisló mediante cultivo celular usando células MDCK. Los resultados obtenidos demostraron la presencia del virus en todos los planteles muestreados. Hubo al menos dos muestras positivas a RT-PCR en tiempo real por granja. De las muestras sometidas a RT-PCR en tiempo real un 22,26% de ellas fueron positivas. Además se lograron aislar con éxito un total de 20 virus desde hisopos nasales y 2 desde fluidos orales, que corresponden a un 8,30% de las muestras obtenidas. Estos resultados indican que SIV es un patógeno frecuentemente encontrado en planteles de producción intensiva en Chile y altamente distribuido a nivel geográfico (desde la V a la VII región), por tanto podría considerarse endémico. / Swine Influenza virus (SIV) is an important respiratory pathogen in intensive pig population, generating significant economic losses for the industry. Also, SIV is a zoonotic pathogen with pandemic potential. Since the 2009 human pandemic caused by a swine origin Influenza virus H1N1, the concern about this pathogen in pigs has been increased. Then, is urgent to understand the dynamics of evolution and transmission of this virus, for animal and public health. The information about SIV in Chile is scarce; therefore any effort to understand or evidence SIV in the country is highly valuable. The aim of this study was the detection and isolation of SIV in intensive swine farms in central Chile, place where most of the pig are raising. Nasal swabs and oral fluids were collected from six farms (V, RM, VI and VII Regions) during 2014-2015 at different seasons through the year. Samples were tested by real time RT-PCR and virus isolation was attempted in canine kidney cells (MDCK). The results showed the presence of SIV in all farms tested. At least 2 samples per farm tested positive by real time RT-PCR. Overall results by real time RT-PCR have shown a 22.3% positive samples. Also, virus isolation was succeeding in 20 nasal swabs and 2 oral fluids, corresponding to 8.30% of the samples collected. Results indicate that SIV is widespread in pig population in the region can be considered endemic. / Financiamiento: Proyecto Aislamiento, diagnóstico y caracterización de virus influenza A en producción intensiva porcina nacional, 2014 Zoetis-Favet Etapa 1.

Three main research products are reported in this dissertation. This research focused on estimation of the seroprevalence rates in agricultural workers with exposure to pigs and poultry, and determination of risk factors for infection. Chapter 2, "Are swine workers in the United States at increased risk of infection with zoonotic influenza virus?", reports controlled, cross-sectional seroprevalence studies among farmers, meat processing workers, veterinarians, and control subjects. Using a hemagglutination inhibition assay against six influenza A virus isolates, all 3 exposed study groups demonstrated markedly elevated titers against the H1N1 and H1N2 swine influenza virus isolates, compared with control subjects. Chapter 3, "Infection due to 3 avian influenza subtypes in United States veterinarians", describes a controlled, cross-sectional seroprevalence study that examined veterinarians in the United States for evidence of previous avian influenza virus infection. Using a microneutralization assay against 9 influenza A virus strains, veterinarians exposed to birds demonstrated statistically significant elevated titers against the H5, H6, and H7 avian influenza virus isolates compared with control subjects. In chapter 4, "Cases of swine influenza in humans: a review of the literature", all known human cases of swine influenza are compiled and analyzed. Fifty cases of apparent zoonotic swine influenza virus infection, including 37 civilians and 13 military personnel, were identified, with a case-fatality rate of 14% (7 of 50 persons). Most civilian subjects (61%) reported exposure to swine. These studies provide strong evidence that transmission of zoonotic influenza likely occurs much more frequently than previously thought, and that individuals with occupational exposure to pigs and birds are at elevated risk for acquiring zoonotic influenza infections. Agricultural workers should be included in pandemic influenza planning, should receive information and training on how to use personal protective equipment, and should be offered human influenza vaccine to reduce the risk of creating viral reassortants. In the event of a pandemic, workers should be considered for antiviral medications and pandemic strain vaccines.